fix key error #177

	name: Validate XML

	on:
	push:
	paths:
	- '**.xml'
	pull_request:
	paths:
	- '**.xml'

	jobs:
	validate-xml:

	runs-on: ubuntu-latest

	steps:
	- name: Check out repository
	uses: actions/checkout@v3

	- name: Set up Python
	uses: actions/setup-python@v4
	with:
	python-version: '3.x'
	cache: 'pip'

	- name: Install dependencies
	run: pip install -r processing/requirements.txt

	- name: Validate XML using Relax NG
	run: python processing/validate.py

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